Coke chute systems and methods therefor

ABSTRACT

Improved coke chute systems ( 100 ) include a lock ( 130 ) that receives and automatically secures a coke-receiving conduit ( 110 ) to a coke vessel after the lock ( 130 ) is switched to a closed position. Contemplated systems may further be combined with a horizontally movable coke chute cover, or a cover that is moved by an actuator ( 114 ) that lifts and rotates the cover from a first position to a second position.

[0001] This application claims the benefit of U.S. provisionalapplication No. 60/203,986, filed May 12, 2000, incorporated herein byreference in its entirety.

FIELD OF THE INVENTION

[0002] The field of the invention is coke chute systems.

BACKGROUND OF THE INVENTION

[0003] Many refineries recover valuable products from the heavy residualoil that remains after refining operations are completed. This recoveryprocess, known as delayed coking, produces valuable distillates and cokein one or more large vessels known as coke drums or coking vessels. Asused herein, coking drums and vessels are used interchangeably. Theoperating conditions of delayed coking can be quite severe with normaloperating pressures typically in the range from about 15 to about 60pounds per square inch, and temperatures exceeding 900° F. The productof the delayed coking process is typically a solid coke, which isfurther processed and cut prior to removal from the coke drum.

[0004] Coke recovery begins with a cooling step in which steam and waterare introduced into the coke filled vessel to complete the recovery ofvolatiles and to cool the mass of coke. The vessel is then vented toatmospheric pressure and the top head (typically a 4-foot diameterflange) is unbolted and removed. The vessel is drained and the bottomhead (typically a 7-foot diameter flange) is unbolted and removed. Ahydraulic coke cutting apparatus is inserted into the vessel to cut thecoke. The hydraulically cut coke falls out of the vessel and into arecovery chute to be channeled to a coke pit or pad. Typically, therecovery chute replaces the removed bottom head so that coke fallingthrough the opening created by removal of the bottom head immediatelyenters the recovery chute.

[0005] While ideally all of the coke is captured by the chute and fallsthrough to a coke pit below, in practice there is spillage, andessentially all of the coke is taken to be channeled through to the cokepit as long as no more than a few percent of coke spills onto the floor.However, it is common to have at least some spillage whenever the headis removed, and such spillage is undesirable both because it results inextra work in cleaning up the spillage, and because it poses a threat toworkers. Spillage frequently occurs during bottom head removal, andoccasionally occurs after head removal but before the coke chute ispositioned, especially when shot coke is produced.

[0006] Attempts to prevent spillage and to reduce risk to workers havebeen made, and can generally be categorized as (1) automating theopening or deheading of the coking vessel, and (2) automating thepositioning of the coke chute. Automating the deheading of the cokingvessel decreases the risk to workers because they need not be presentduring the initial opening of the vessel when spillage frequentlyoccurs. However, decreasing the risk to workers in this matter does noteliminate the spillage during the opening process. Moreover, if thepositioning of the coke chute is not automated, the workers are at riskwhile positioning the coke chute. Even with an automated chutepositioning system, there is a chance that spillage, itself undesirable,will occur prior to the chute being positioned.

[0007] Thus, there is a further need for an improved system which willallow coke to be discharged from a coking vessel without placing workersat risk such as by requiring workers to position a coke chute afteropening an outlet in the coking vessel, and which will prevent spillagewhile opening an outlet in the coking vessel.

SUMMARY OF THE INVENTION

[0008] The present invention is directed to improved coke chute systemsthat include a coke receiving conduit coupled to an actuator moving theconduit between a first position and a second position, wherein theconduit is further coupled to a contactor. Contemplated systems furtherinclude a lock having an opened position and a closed position, andfurther comprising a latch, wherein the lock is coupled to a cokevessel, wherein the contactor engages with the latch and secures theconduit relative to the coke vessel when the conduit moves from thefirst position to the second position and when the lock is in the closedposition, and wherein the latch disengages the latch when the lock isswitched to the opened position.

[0009] In one aspect of the inventive subject matter, the coke-receivingconduit comprises a telescoping coke chute, the actuator comprises ahydraulic cylinder, and the contactor comprises a roller. It is furtherpreferred that the latch may have a curved locking surface that contactsthe contactor when the conduit moves from the first position to thesecond position. In yet further preferred aspects, first position of theconduit is a position in which the conduit is substantially level withan operating platform, and wherein the conduit is fluidly coupled to anopening of the coke vessel in the second position. Preferred switchingof the lock comprises manually switching.

[0010] In another aspect of the inventive subject matter, a coke chutecover has a frame and a cover coupled to the frame, and a wheel iscoupled to the frame, wherein the frame further comprises a guideelement, and a bracket coupled to an actuator moves the frame between afirst position and a second position, wherein the wheel and the guideelement move along the rail, and wherein the frame covers at least partof a flow path of coke between a coke vessel outlet and a coke chutewhen the frame is in the first position.

[0011] In a further aspect of the inventive subject matter, pivotingcoke chute cover comprises a cover having a first extension and a secondextension, wherein the first extension is coupled to an actuator thatlifts and rotates the cover between a first position and a secondposition, wherein the second extension is coupled to a wheel, andwherein the cover covers at least part of a flow path of coke between acoke vessel outlet and a coke chute when the frame is in the firstposition. One or both contemplated coke chute covers may be combinedwith contemplated coke chute system.

[0012] Various objects, features, aspects and advantages of the presentinvention will become more apparent from the following detaileddescription of preferred embodiments of the invention, along with theaccompanying drawings in which like numerals represent like components.

BRIEF DESCRIPTION OF THE DRAWING

[0013]FIG. 1 is a schematic side view of an exemplary coke chute system.

[0014]FIG. 2 is a schematic front view of one exemplary coke chutecover.

[0015]FIG. 3 is a schematic top view of another exemplary coke chutecover.

DETAILED DESCRIPTION

[0016] It is generally contemplated that improved coke chute systemsaccording to the inventive subject matter may comprise a system, inwhich a movable coke receiving conduit is releasably secured to a cokedrum or coke drum outlet to receive coke after a coking process. Furthercontemplated improved coke chute systems may include a cover that coversa coke receiving conduit, wherein the cover moves horizontally along alinear or curved path. Contemplated covers may be lifted prior or duringthe movement.

[0017] More particularly, as shown in FIG. 1, an improved coke chutesystem 100 has a coke receiving conduit 110 (here: in a raised position)that further comprises a conduit lift ring 112 which is coupled to ahydraulic actuator 114 to move the coke receiving conduit 110 from alowered to a raised position. In the raised position, the coke receivingconduit 110 is fluidly coupled to the coke drum or coke drum outlet 150via a bottom flange 152. A contactor 120 is coupled to the conduit liftring 112 and engages with the latch 138 of lock 130. The lock 130further comprises an actuating lever 132 coupled to an actuator handle136. Latch spring 134 assists in retaining the latch 138 in a closedposition. The lock 130 is preferably mounted to the coke drum or cokedrum outlet 150 via a mounting bracket 140.

[0018] In a preferred aspect of the inventive subject matter, the cokereceiving conduit is a telescoping coke receiving conduit, in which theuppermost portion is at or below the upper surface of a platform onwhich an operator may stand or walk when the coke receiving conduit isin a lowered position. When the telescoping coke receiving conduit is ina raised position, the uppermost portion of the conduit fluidly coupleswith an outlet of a coke drum or coke drum outlet. While not critical tothe inventive subject matter, it is preferred that the uppermost portionof the conduit may further comprise a skirt or funnel-shaped extensionwhich may guide the conduit in a desired position and/or may preventspillage of coke from the coke drum. It is further preferred that thecoke receiving conduit is moved between the lowered and raised positionby an automatic mechanism, and particularly contemplated automatedmechanisms include hydraulic and/or pneumatic cylinders, cable lifts,raising gear, etc.

[0019] In alternative aspects, the coke receiving conduit need not belimited to a telescoping coke receiving conduit, and numerousalternative coke receiving conduits are also contemplated so long assuch conduits approximate the coke drum or coke drum outlet from adistal position. The term “distal position” as used herein refers to anyposition that is at least 30 cm, more typically at least 100 cm, andeven more typically at least 150 cm away from the coke drum outlet. Forexample, where the headspace between the platform and the coke drumoutlet is relatively limited, appropriate coke receiving conduits mayalso move along a horizontal path or along a curved path towards thecoke drum outlet. On the other hand, and especially where no operatingplatform is disposed below the coke drum outlet, suitable conduits maybe provided by a coke receiving or storage structure (e.g., rail wagon).Consequently, various actuating mechanism other than hydraulic cylindersare also contemplated. In fact, all reasonable mechanism or modes ofmoving the coke receiving conduit towards the coke drum outlet arecontemplated, including automated methods (supra), manual methods, andany combination thereof. Similarly, suitable coke receiving conduits mayor may not have a conduit lift ring. For example, where the conduit ismoved by a plurality of steel cables, the ring may be replaced by hooksor loops attached to the conduit. On the other hand, where a crankactuates the conduit, a crank rail may be coupled to the conduit. Whileit is generally preferred that the conduit is at or below the uppersurface of a platform on which an operator may stand or walk when thecoke receiving conduit is in a lowered position, numerous alternativepositions are also contemplated, including positions above the uppersurface of the platform.

[0020] With respect to the contactor, it is preferred that the contactorcomprises a metal rod that is tangentially coupled to the lift ring(e.g., in a cutout of the lift ring), and that has at least a portionthat can engage with the latch of the lock. It is generally preferredthat contemplated conduits comprise at least three contactors. However,depending on the size of the conduit and the mode of movement o theconduit, it is contemplated that the number of contactors may varyconsiderably. For example, where the conduit is rotatably coupled to thecoke drum outlet one or two contactors may be appropriate. On the otherhand, where the conduit is a telescoping conduit, three or morecontactors are preferred. While it is generally preferred that thecontactor has a rod-shape, it should be appreciated that numerousalternative shapes and sizes are also suitable, so long as at least aportion of the contactor can contact the latch. For example, appropriatecontactors may have a curved shape (e.g., U-shaped), or may comprise aspherical extension (e.g., pear-shaped protrusion). In still furtheralternative other aspects, the contactor may include a movable element(e.g., a roller or wheel) that may at least in part contact the latch.

[0021] In still further preferred aspects of the inventive subjectmatter, contemplated coke chute systems include a lock that is coupledvia a mounting bracket to either the coke drum or a coke drum outlet(which may or may not have a bottom flange). Especially contemplatedlocks comprise a latch and a latch spring that assists in holding thelatch in a closed position. Contemplated locks may further comprise anactuating lever that can be switched (typically by using an actuatorhandle) between a first and second position, wherein the lever forcesthe latch into an opened position when the lever is in the firstposition, and wherein the lever releases the latch into the closedposition, when the lever is in the second position (see also FIG. 1,hatched and solid lines).

[0022] In a particularly preferred aspect, the latch comprises a curvedsurface and a locking notch, wherein the latch is rotatably coupled tothe lock such that the contactor proceeds along the curved surface tothe locking notch as the conduit is raised from a lowered to a raisedposition. During this “up-latch” process, the latch pivots around apivot point (which is typically the point of coupling of the latch tothe rest of the lock) until the contactor reaches the locking notch onthe latch. An optional latch spring on the lock provides counter forceto assist retaining close contact between the latch (typically thecurved surface and the notch) and the contactor as the contactor movesbetween the curved surface and the notch. An actuating lever (here:manually operated) may be employed to pivot the latch such that thecontactor and the latch disengage (i.e., to switch the lock in an openposition). With respect to the latch it should be appreciated thatnumerous alternative configurations are also appropriate. For example,where appropriate the curved surface may be modified to a straightsurface. Furthermore, and especially where redundant safety features arerequired more than one locking notch may be employed in the latch. Inother aspects, the latch spring may be substituted or assisted byvarious alternative mechanisms, including gas springs, hydraulics, motorassisted mechanisms, etc. Similarly, the actuating lever may be operatedby an automatic mechanism (e.g., motor, hydraulics, etc.) where remoteoperation is particularly desirable. With respect to the number oflocks, the same considerations as for the contactors apply.

[0023] Thus, it is contemplated that the conduit is secured in aposition relative to the coke drum while the lock remains in a lockedposition. It should further be appreciated that no active opening stepis needed in securing the conduit in a position relative to the cokedrum. Consequently, a preferred method of operating the improved cokechute system includes a step in which an operator switches the lock in alocked position. In a second step, the conduit is moved towards the cokedrum or coke drum outlet and the latch engages with the contactor as theconduit approximates the coke drum or coke drum outlet (thereby securingthe conduit is a position relative to the coke drum). In yet anotherstep, the operator switches the lock in the open position (therebydisengaging the contactor and the latch), and the conduit can be loweredfrom the raised position into a lower position. While it is generallypreferred that the lock is manually opened and closed by an operator,alternative modes of operating the coke chute system are alsocontemplated and include automatic operation of the lock in at least onedirection. Similarly, it should be appreciated that the conduit may beraised or lowered manually or automatically.

[0024] In still further contemplated aspects of the inventive subjectmatter, contemplated coke chute systems may further (or additionally)comprise a cover mechanism that covers the coke receiving conduit. Suchcovers are particularly advantageous the conduit is substantially levelwith an operating platform when in a lowered position (and wherein theconduit fluidly couples with an opening of the coke vessel in the raisedposition). FIG. 2 depicts an exemplary cover mechanism 200, in which acoke receiving conduit 280 is in a lowered position and substantiallylevel with a platform 205 on which an operator can stand or walk. Thecover mechanism includes a frame 210 onto which a cover 220 is mounted.The frame 210 further comprises a wheel 230 that runs on a rail 270, andthe frame may additionally comprise a guide element 240 that guides theframe along the rail 270. The frame 210 is moved in a horizontaldirection (substantially parallel to the platform) by an actuator 260,which is disposed within an opening within the platform 205. Theactuator is coupled to the frame by bracket 250, and an actuator cover262 protects the actuator from the operating environment.

[0025] While not limiting the inventive subject matter, it is generallypreferred that the actuator 260 comprises a hydraulic cylinder that isat least partially disposed in a corresponding cutout or trench withinthe platform. The actuating force is preferably transmitted via abracket. However, in further aspects, numerous alternative actuators maybe employed, including automatic actuators (e.g., motor operated,pneumatic, crank-driven, etc.) or manual actuators (i.e., actuators inwhich the actuating force is at least partially provided by anoperator). It is further preferred that the frame, cover, guide element,and bracket are manufactured from stainless steel or other, metallicmaterial, however, where appropriate alternative materials may also beemployed. Particularly preferred covers comprise a grating, andparticularly suitable materials include wood, synthetic polymers,aluminum, and all reasonable combinations thereof. It should further beappreciated that the size of the frame and cover will predominantlydepend on the size of the coke receiving conduit and/or the openingthrough which the coke receiving conduit passes from the loweredposition to the raised position. Thus, a typical frame will measurebetween about 60 cm-300 cm in width and approximately 60 cm-300 cm inlength. However, larger covers are also contemplated.

[0026] With respect to the rail and actuator it is preferred that atleast one of the rail and actuator are at least partially disposedwithin the platform (e g., in a trench, or partially or completelyembedded) in separate locations. However, where appropriate, the railand the actuator (or alternative mechanism, supra) may also be disposedin a common structure. It should still further be appreciated that wherethe actuator is disposed within a trench that the trench may be coveredby an actuator cover to protect the actuating mechanism from theoperating environment. Contemplated cover mechanisms 200 are preferablyoperated from a remote location using suitable control circuits (e.g.,to prevent movement of the cover while an operator stands or walks onthe cover.

[0027] Alternatively, and especially where it is desired that the coveris substantially flush with the platform, a lifting and rotatingactuator mechanism may be employed as depicted in FIG. 3. Here, a covermechanism 300 has a lifting and rotating actuator 310 that is coupled toa first extension 320 of the frame 370, to which a cover 360 is coupled.A pair of second extensions 330 is coupled to the frame 370 and each ofthe second extensions 330 has a wheel 335 that rolls on the rail 340which is at least partially disposed in the platform 350. A cokereceiving conduit 350 is disposed underneath the platform when theconduit is in a lowered position.

[0028] With respect to the lifting and rotating actuator, it ispreferred that the actuator comprises a hydraulic cylinder that liftsthe cover sufficiently high such that the lower surface of the cover isabove the upper surface of the platform, and such that the cover can berotated along the rail over the platform. While it is preferred that therotating movement is automated (e.g., by a motor, hydraulic cylinder, orcrank gear), alternative embodiments may employ manual rotation of thecover. Automated rotation may be imparted by rotating the hydrauliccylinder while the cover is in a fixed position relative to thehydraulic cylinder, or by rotatably coupling the hydraulic cylinder tothe cover.

[0029] It is further contemplated that the first extension is directlyattached to the frame and that the platform has corresponding cutouts oropenings to accommodate the frame, cover, and the first and secondextensions (including the wheels) when the cover is in a closed position(i.e., when the cover is substantially flush with the upper surface ofthe platform). With respect to the size, shape and numbers of the firstextension it should be appreciated that numerous sizes shapes andnumbers are suitable so long as the first extension couples the liftingand rotating actuator to the platform and so long as alternative firstextensions allow lifting and rotating the frame and cover. Thus,alternative first extensions may comprise one or more steel rods orplates, and may be welded or bolted to the frame or cover. Similarly,the size, shape and numbers of the second extensions may varyconsiderably and it should be appreciated that numerous sizes shapes andnumbers are suitable so long as the second extensions couple the wheelsto the frame or cover, and so long as alternative second extensionsallow rotating the frame and cover. With respect to material and shapeof the frame and cover, the same considerations as described aboveapply.

[0030] Particularly preferred wheels include stainless steel wheels ofapproximately 5 cm in outer and it is further preferred that each secondextension has at least one wheel. However, there are numerousalternative wheels known in the art and all such wheels are consideredsuitable for use herein as long as the wheel(s) support the cover andallow rotation of the cover along the rail. Consequently, the rail ispreferably a steel rail with an upper surface that is flush with theupper surface of the platform. While it is generally preferred that thelifting and rotating mechanism is automated, it should also beappreciated that at least one of the movements may be manually.

[0031] In still further preferred aspects of the inventive subjectmatter, contemplated cover mechanisms (as depicted in FIGS. 2 and 3) maybe combined with contemplated coke chute systems (as depicted in FIG. 1)thereby advantageously increasing the safety of operation around cokedrums.

[0032] Thus, specific embodiments and applications of improved cokechute systems have been disclosed. It should be apparent, however, tothose skilled in the art that many more modifications besides thosealready described are possible without departing from the inventiveconcepts herein. The inventive subject matter, therefore, is not to berestricted except in the spirit of the appended claims. Moreover, ininterpreting both the specification and the claims, all terms should beinterpreted in the broadest possible manner consistent with the context.In particular, the terms “comprises” and “comprising” should beinterpreted as referring to elements, components, or steps in anon-exclusive manner, indicating that the referenced elements,components, or steps may be present, or utilized, or combined with otherelements, components, or steps that are not expressly referenced.

What is claimed is:
 1. A coke chute system comprising: a coke chutecoupled to an actuator that moves the coke chute between a firstposition and a second position, wherein the coke chute is furthercoupled to a contactor; a lock with a latch having an open position anda closed position and coupled to a coke vessel; wherein the contactorengages with the latch in the closed position and automatically securesthe coke chute relative to the coke vessel when the coke chute movesfrom the first position to the second position; and wherein thecontactor disengages the latch in the opened position.
 2. The system ofclaim 1 wherein the coke receiving conduit comprises a telescoping cokechute.
 3. The system of claim 1 wherein the actuator comprises ahydraulic cylinder.
 4. The system of claim 1 wherein the contactorcomprises a roller.
 5. The system of claim 1 wherein the latch comprisesa curved portion that engages with the contactor.
 6. The system of claim5 wherein the curved portion contacts the contactor as the conduit movesfrom the first position to the second position.
 7. The system of claim 1wherein the first position is a position of the conduit in which theconduit is substantially level with an operating platform, and whereinthe second position is a position of the conduit in which the conduit isfluidly coupled with an opening of the coke vessel.
 8. The system ofclaim 1 wherein switching of the lock comprises manually switching thelock from the opened position to the closed position.
 9. The system ofclaim 1 further comprising the coke chute cover of claim
 11. 10. Thesystem of claim 1 further comprising the coke chute cover of claim 15.11. A coke chute cover comprising: a frame and a coke chute covercoupled to the frame; a wheel coupled to the frame, wherein the framefurther comprises a guide element, and a bracket coupled to an actuatorthat moves the frame between a first position and a second position; andwherein the wheel and the guide element move along the rail, and whereinthe coke chute cover covers at least part of a flow path of coke betweena coke vessel outlet and a coke chute when the frame is in the firstposition.
 12. The coke chute cover of claim 11 wherein the actuatorcomprises a hydraulic cylinder.
 13. The coke chute cover of claim 11wherein at least one of the rail and the actuator are at least partiallydisposed within a platform.
 14. The coke chute cover of claim 11 whereinthe cover comprises a grating.
 15. A pivoting coke chute covercomprising: a coke chute_cover coupled to a first extension and a secondextension, wherein the first extension is coupled to an actuator thatlifts and rotates the coke chute cover between a first position and asecond position, and wherein the second extension is coupled to a wheel;and wherein the coke chute cover covers at least part of a flow path ofcoke between a coke vessel outlet and a coke chute when the frame is inthe first position.